Understanding DNA Damage and Repair

What is DNA damage and what are its main types?

What causes thymine dimer formation?

• UV radiation from the sun or tanning beds

• Chemical changes to individual DNA bases

• Ionizing radiation

• Covalent bonds between DNA strands

What are the consequences of thymine dimers?

• Distortion of the DNA helix

• Mispairing during replication

• Breaks in the DNA double helix

• Covalent bonds between DNA strands

What are the endogenous causes of DNA damage?

What is the mechanism of Base Excision Repair (BER)?

What are the consequences of unrepaired DNA damage?

What is the consequence of failure in Nucleotide Excision Repair (NER)?

• Point mutations

• Skin cancer

• Chromosomal rearrangements

• Cell death

What happens during apoptosis?